BrilLanCe\texttrademark~detector characterization below $E_{\gamma}= 15.5$ MeV*

Lanthanum-halide crystals represent a major step in finding a room temperature photon detector having high efficiency and good timing and energy resolution over a wide range of energies. These detectors are presently being marketed under the tradename of BrilLanCe\texttrademark . We have studied the preformance of these detectors between 2.5 and 15.5 MeV using $\gamma$-ray beams produced by the HI$\vec{\gamma}$S facility. Gaussian fits to the BrilLanCe\texttrademark detector spectra were corrected for the beam energy spread to obtain the detector resolution. A 10.16 cm (diameter)x 15.24 cm(long) LaCl$_{3}$(Ce) detector and a 7.62 cm x 7.62 cm LaBr$_{3}$(Ce) detector are characterized in the present study. The energy resolution of each detector will be reported as a function of incident $\gamma$-ray energy from 2.5 to 15.5 MeV. In addition the response of these detectors to thermal neutrons will be described.